Federal auditors are investigating whether $25 million in Sandy relief funds were improperly used for a marketing campaign, starring Gov. Chris Christie and his family, to promote tourism as he was gearing up for his 2013 re-election bid, according to U.S. Rep. Frank Pallone, D-N.J.

Pallone, a 27-year House veteran and vocal Christie critic, announced Friday that the inspector general of the Department of Housing and Urban Development, at his request, has conducted a preliminary review of the spending.

He said the IG concluded that there is enough evidence to launch a full-scale investigation into the state's use of federal funds, the Asbury Park Press reported.

The probe will look into how Christie, a Republican, chose to spend the marketing money approved by the department.

Pallone said the audit by the IG will take several months, and the findings will be issued in an official report.

The congressman said he was concerned about the bidding process for the firm that was awarded the marketing plan, which was aimed at luring tourists back to an area badly battered by Superstorm Sandy in October 2012.

"This was money that could have directly been used for Sandy recovery. And, as you know, many of my constituents still haven't gotten the money that is owed them to rebuild their homes or raise their homes or to help," Pallone said.The winning firm, Pallone told CNN, charged the state $4.7 million, about $2 million more than the next lowest bidder, whose proposal did not feature the Christie family.

To earlier criticism by Democrats that the ads gave Christie an unfair advantage in the leadup to the election, Christie aides said last summer that the winning bid provided more value.

In November, Republican Sen. Rand Paul of Kentucky also criticized the ads, asking HUD secretary Shaun Donovan at a committee hearing whether it was appropriate to permit the New Jersey state government to use federal relief dollars to fund the ad campaign.While Donovan declined to take a position, Paul weighed in with his own views, slamming people "running for office (who) put their mug all over these ads while they're in the middle of a political campaign."

"In New Jersey, $25 million was spent on ads that included somebody running for political office," Paul said. "I'm thinking there might be a conflict of interest there. That's a real problem. And that's why, when people are trying to do good and trying to use the taxpayer's money wisely, they're offended to see our money spent on political ads. That's just offensive."

Paul noted that New York state has aired similar tourism ads, but that state law barred state officials from appearing on-camera, The Washington Post reports. .